Cryptarcus is a genus of ceratopsid dinosaur found in the Dinosaur Park Formation of Alberta, dating to the middle Campanian age of the Late Cretaceous.
Cryptarcus is a genus of ceratopsid dinosaur found in the Dinosaur Park Formation of Alberta, dating to the middle Campanian age of the Late Cretaceous.
It was first named in 1940 by Charles Mortram Sternberg as a species of the genus Chasmosaurus and given the name Chasmosaurus russelli. The specific name honored Loris Shano Russell, who discovered the first known specimen. It was recognized as part of this genus for several subsequent decades. Throughout the early 21st century it would be considered one of two species of Chasmosaurus, alongside C. belli, and many specimens would be referred to it. However, differences between the original specimen (a nearly complete skull) and other supposed C. russelli specimens were noted, prompting reassessment. New work on the specimen was published in 2026, concluding the former was a distinct species from most of the others. Therefore, it was made the type species of the new genus Cryptarcus, with a partial parietal as the only other specimen retained within the species. While its relationships remain uncertain, it may be more closely related to animals such as Utahceratops and Pentaceratops rather than Chasmosaurus.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).